946 ASCLEPI ADACE A E 



with a salient, acute or obtuse tooth or lobe on each side near the base : horn short, 

 broadly falcate-subulate, incurved over the anthers: follicles very slender, 10-12 cm. 

 long, erect on erect fruiting pedicels, linear-fusiform, glabrous : seeds 6 mm. long, pale 

 brown when fresh, very thin : coma 3-4 cm. long. 



In dry soil, woods and thickets, Maine and Ontario to Minnesota to North Carolina and Arkansas. 

 Spring and summer. 



16. Asclepias incarnata L. Stems glabrous or minutely pubescent, 6-10 dm. high 

 or more, usually branched and often pubescent in lines above, very leafy : leaves opposite ; 

 blades manifestly petioled, 4-17 cm. long, oblong-lanceolate, acuminate at the apex, obtuse 

 or obscurely subcordate at the base, thinnish, with sometimes a few scattered hairs beneath : 

 umbels rather small, several, corymbose at the summit of the stem, many-flowered : pedi- 

 cels 1-1.5 cm. long, minutely pubescent : corolla deep rose-purple to pale pink or rarely 

 white ; lobes oblong, 4-6 mm. long : hoods scarcely exceeding the stigmas, erect on the 

 distinct (1-1.5 mm. high) slender column, oblong, obtuse at the apex, the rounded ventral 

 margins overlapping on the inside, dorsally biauriculate-hastate at the base, slightly 

 exceeded by the slender incurved horn : anther-wings minutely notched at the base : 

 follicles erect on erect fruiting pedicels, 5-7 cm. long, ovoid-fusiform, acuminate at the 

 apex, glabrous or minutely pubescent : seeds 7-11 mm. long, red-brown, shining, minutely 

 granulose under a lens, the margins paler, very thin and papery : coma about 2 cm. long. 



In swamps, New Brunswick to the Northwest Territory. Kansas, Tennessee and Louisiana. Summer. 

 A. incarnata longifdlia A. Gray, is between 1 and 2 m. tall, and has paler flowers and greatly elon- 

 gated leaf-blades ; it occurs in Texas and New Mexico. 



17. Asclepias pulchra Ehrh. Stems hirsute-pubescent, 5-1.5 dm. high, branched 

 above, very leafy to the top : leaf-blades short-petioled or some of the upper ones sessile, 

 broadly lanceolate, lanceolate-oblong or oblong, 6-12 cm. long, 3-5.5 cm. wide, acute or 

 acuminate at the apex, mostly rounded or subcordate and rarely subhastate at the base : 

 umbels numerous, corymbose, about 3 cm. broad, many-flowered : pedicels 15 mm. long, 

 hirsute-pubescent : corolla small, rose-purple, rarely white ; lobes obtuse, often notched : 

 column 1 mm. high, very slender but distinct : hoods erect, 2 mm. high, oblong, obtuse, 

 slightly exceeding the anthers, dorsally biauriculate-hastate at the base, the ventral mar- 

 gins infolded : horn flat, slender, exserted-incurved over the anthers : anther-wings notched 

 at the base : follicles erect on erect fruiting pedicels, 4 cm. long, slender, acuminate, 

 minutely hirsute-pubescent : seeds 8-10 mm. long, 5-7 mm. wide, the apex often crenate : 

 coma 2 cm. long. [A. incarnata var. pulchra Pers.] 



In moist fields and swamps, Maine to Minnesota and Georgia. Summer and fall. 



18. Asclepias Curassavica L. Stems somewhat woody at the base, glabrous or 

 minutely pubescent above, 3-6 dm. high or more : leaves opposite ; blades 5-10 cm. long 

 or more, oblong to oblong-lanceolate, commonly acuminate : umbels terminal and lateral, 

 5-10-flowered : pedicels 1-2 cm. long : corolla-lobes deep red-purple, 6-8 mm. long, ovate- 

 oblong : column distinct : hoods erect, 4 mm. high, ovate, obtuse at the broad apex, laterally 

 compressed, shorter than the flat broad attenuate curved horn, which arises from the 

 slightly gibbous base of the hood : follicles erect on erect fruiting pedicels, 3-10 cm. long, 

 slender-fusiform, acuminate, glabrous or minutely pubescent and slightly glaucous : seeds 

 6 mm. long, rather thin : coma 3-4 cm. long. Plants very variable as to length and 

 breadth of the leaves. 



In sandy soil, western Florida and Louisiana. Probably introduced from tropical America. 

 Known from nearly all warm countries. Spring to fall. 



19. Asclepias perennis Walt. Stems puberulent above, glabrous below, woody at 

 the base from a short clustered rootstock, simple or sometimes branched, 3-9 dm. high, 

 slender : leaf-blades 5-15 cm. long, oblong-lanceolate or rarely lanceolate, acuminate or 

 acute at each end, thin : umbels solitary or when several together corymbose : pedicels 

 1-2.5 cm. long, slender : flowers small, mainly white : corolla-lobes oblong, 2-3.5 mm. long, 

 tipped with dull pink on the outside : column slender but distinct : hoods oval, erect, entire, 

 obscurely sagittate-hastate on the back at the base, not exceeding the top of the anthers 

 and shorter than the filiform incurved horn : follicles erect on erect fruiting pedicels, 5-8 

 cm. long, ovoid-fusiform, acuminate above, tapering at the base, glabrous: seeds 11.5 

 mm. long, thin, oblong-orbicular, rounded at the apex, tapering to the much narrower 

 base, apparently destitute of coma, the margin 2-3 mm. wide, undulate. 



On wet and muddy shores, Indiana to Missouri, Florida, Louisiana and Texas. Spring and summer. 



20. Asclepias Texana Heller. Stems glabrous or minutely pubescent : simple from 

 a woody base, 3-5 dm. high, cymosely branched, gray-green and glaucous above, purplish 

 below, commonly marked with 1 or 2 narrow pubescent lines : leaves opposite ; blades 2.5-4 

 am. long, oval-oblong, acutish at the apex, broader, obscurely oblique or even truncate 

 end sometimes also tapering at the base ; petioles 1-14 cm. long, slightly margined : 



